Yes it is skin.
Triangle attack seem to be be pre-determined and is more of an magic animation then a battle animation. It seem to be based on the characters and in the case of Binding Sword it will use Bor’s and the other’s generic colors and General sprite, even if they are replaced. Might be best to check Custom Triangle Attacks: A Guide
Since Triangle attack uses a different sort of insertion.
Also, vanilla color wise it is already as vanilla as possible however if you mean to use the pallet string for vanilla color, that would be impossible. Each of the pallet has a set place and if you just paste a string from the original (in this case the Original General) it won’t work due to limited colors it has since original general doesn’t have skin or hair as well as the placement of the vanilla colors are completely different (this is on purpose cause I organized it to be so to make it easier to figure out which color is which, meaning each of the 3-4 colors are always together for a certain part i.e slot 4-7 is trimming/leg and slot 12-15 is the armor itself). This also means that you can’t just lace a specific character’s color over it (as explained in the readme, if you try to put Lyn’s as-is default color, it will be messed up so instead you will have to DYI to make it fit)
To keep vanilla color you have to look at each one and put them in the proper place yourself which shouldn’t be too hard since each slot is labeled and you just need to paste the singular color to the slot. In all and all, this is more of a custom sprite than a full on 1v1 replace, although it shares the same animation as much as possible.